// 生成字母编号
export function createChars(num: number) {
  let char = '';
  const at = Math.floor(num / 26);
  const letters = 'ABCDEFGHIJKLMNOPQRSTUVWXYZ'.split('');
  let les = letters[at - 1];

  for (let i = 0; i < 26; i++) {
    if (num / 26 >= 1) {
      letters[i] = les + letters[i]
    }
  }
  if (at < 1) {
    char = letters[num - 25 * at];
  } else {
    char = letters[num - 25 * at - at];
  }
  return char;
}